Fabrication or manufacture of semiconductor devices typically is accomplished through the use of a silicon wafer or the like which is treated within a plasma reactor assembly. Layers of different elements or components are formed on the wafer by, for example, depositing the element or compound onto the wafer and then etching the element to provide the desired layout.
The plasma reactor assembly may be used for depositing the desired material onto the wafer or for etching the material from the wafer. The plasma reactor assembly may include a chamber and upper and lower electrodes. The wafer typically rests on and is in electrical contact with the lower electrode.
After repeated use of the plasma reactor assembly, however, the lower electrode must be replaced because the top surface of the lower electrode becomes degraded. Replacement of the lower electrode can be a time intensive process which not only requires man hours but also results in unwanted downtime of the plasma reactor assembly.
Accordingly, it is an object of the present invention to provide an electrode assembly for a plasma reactor assembly for use in connection with fabricating semiconductors that substantially reduces degradation of the surface of the electrode, and, thus, substantially reduces the need to replace the electrode.
It is a further object of the present invention to provide such an electrode assembly that includes a removable ring for covering a relatively large surface area of the electrode.
It is further object of the present invention to provide such an electrode assembly wherein the removable ring has a substantially flat and unobstructed top surface to facilitate placement of the wafer onto the electrode.
It is a further object of the present invention to provide such an electrode assembly that is adapted to reduce coupling between the plasma and a top surface of the electrode.
It is a still further object of the present invention to provide such an electrode assembly wherein the removable ring can be easily and quickly removed and replaced.